org.assertj.core.condition

Class VerboseCondition<T>

java.lang.Object

org.assertj.core.api.Condition<T>

org.assertj.core.condition.VerboseCondition<T>

Type Parameters:

T - the type of object the given condition accept.

All Implemented Interfaces:

Descriptable<Condition<T>>

public final class VerboseCondition<T>
extends Condition<T>

Condition that shows the value under test when the condition fails thanks to the specified objectUnderTestDescriptor function.

When defining the objectUnderTestDescriptor function, you should take in consideration whether the condition is going to be used with is(Condition) or has(Condition) since the start of the error message is different between the two.

Let's see how it works with an example that works well with is(Condition):

 Condition<String> shorterThan4 = VerboseCondition.verboseCondition(actual -> actual.length() < 4,
                                                                   // predicate description  
                                                                   "shorter than 4",
                                                                   // value under test description transformation function
                                                                   s -> String.format(" but length was %s", s.length(), s));

If we execute:

 assertThat("foooo").is(shorterThan4);

it fails with the following assertion error:

 Expecting actual:
   "foooo"
 to be shorter than 4 but length was 5

Note that the beginning of the error message looks nice with is(Condition), but not so much with has(Condition):

 Expecting actual:
   "foooo"
 to have shorter than 4 but length was 5

The objectUnderTestDescriptor must not be null, if you don't need one this probably means you can simply use Condition(Predicate, String, Object...) instead of a VerboseCondition.

Author:

Stefan Bischof

Nested Class Summary

Nested classes/interfaces inherited from class org.assertj.core.api.Condition

Condition.Status

Method Summary

Modifier and Type	Method and Description
protected String	buildVerboseDescription(T objectUnderTest, boolean matches) Build the verbose condition description when applied with the actual values and the match result.
boolean	matches(T objectUnderTest) Verifies that the given value satisfies this condition.
static <T> VerboseCondition<T>	verboseCondition(Predicate<T> predicate, String description, Function<T,String> objectUnderTestDescriptor) Creates a new VerboseCondition to have better control over the condition description when the condition fails thanks to the objectUnderTestDescriptor function parameter.

Methods inherited from class org.assertj.core.api.Condition

conditionDescriptionWithStatus, describedAs, description, status, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.assertj.core.api.Descriptable

as, as, as, describedAs

Method Detail

verboseCondition

public static <T> VerboseCondition<T> verboseCondition(Predicate<T> predicate,
                                                       String description,
                                                       Function<T,String> objectUnderTestDescriptor)

Creates a new VerboseCondition to have better control over the condition description when the condition fails thanks to the objectUnderTestDescriptor function parameter.

When defining the objectUnderTestDescriptor function, you should take in consideration whether the condition is going to be used with is(Condition) or has(Condition) since the start of the error message is different between the two.

Let's see how it works with an example that works well with is(Condition):

 Condition<String> shorterThan4 = VerboseCondition.verboseCondition(actual -> actual.length() < 4,
                                                                    // predicate description  
                                                                    "shorter than 4",
                                                                    // value under test description transformation function
                                                                    s -> String.format(" but length was %s", s.length(), s));

If we execute:

 assertThat("foooo").is(shorterThan4);

it fails with the following assertion error:

 Expecting actual:
   "foooo"
 to be shorter than 4 but length was 5

Note that the beginning of the error message looks nice with is(Condition), but not so much with has(Condition):

 Expecting actual:
   "foooo"
 to have shorter than 4 but length was 5

The objectUnderTestDescriptor must not be null, if you don't need one this probably means you can simply use Condition(Predicate, String, Object...) instead of a VerboseCondition.

Type Parameters:

T - the type of object the given condition accept.

Parameters:

predicate - the Predicate that tests the value to test.

description - describes the Condition verbal.

objectUnderTestDescriptor - Function used to describe the value to test when the actual value does not match the predicate. must not be null.

Returns:

the created VerboseCondition.

Throws:

NullPointerException - if the predicate is null.

NullPointerException - if the objectUnderTestDescriptor is null.

matches

public boolean matches(T objectUnderTest)

Description copied from class: Condition

Verifies that the given value satisfies this condition.

Overrides:

matches in class Condition<T>

Parameters:

objectUnderTest - the value to verify.

Returns:

true if the given value satisfies this condition; false otherwise.

buildVerboseDescription

protected String buildVerboseDescription(T objectUnderTest,
                                         boolean matches)

Build the verbose condition description when applied with the actual values and the match result.

Parameters:

objectUnderTest - the object to test

matches - the result of the match operation

Returns:

the verbose condition description.